1. Field of the Invention
The present invention relates to a dry clutch control method for a vehicle, and more particularly, to a technology of coping with a generation of judder in a dry clutch used in an automated manual transmission (AMT) including a dual clutch transmission (DCT).
2. Description of Related Art
Recently, many attempts to develop a dual clutch transmission (DCT) capable of simultaneously achieving driving convenience of an automatic transmission and fuel efficiency and high power efficiency of a manual transmission have been conducted. The DCT is a kind of an automated manual transmission (AMT) based on a manual transmission system and has two torque transfer shafts to reduce and prevent a reduction of torque during transmission, thereby securing a quality of transmission and is a system automatically controlling a clutch without a torque converter to be configured to increase fuel efficiency.
However, the DCT or the AMT directly fastens the clutch without the torque converter to switch power and therefore clutch control performance dominates launch and transmission performance of a vehicle.
As such, the clutch used in the DCT or the AMT is divided into a wet clutch controlled by an oil pressure and a dry clutch having a mechanical operating scheme of a simple configuration. In the general driving situations, it has been known that the dry clutch has power transfer efficiency 3% higher than the wet clutch and thus the dry clutch has been in the limelight as a fuel efficiency improvement technology.
However, when the dry clutch is overheated as in a case of starting of a vehicle at an uphill road, and the like, the clutch performance may be degraded due to a change in a friction coefficient or the occurrence of vibration of the dry clutch, or the like.
That is, a vibration phenomenon of the dry clutch in a specific slip section depending on a rotating speed difference between an engine flywheel and a clutch disk due to a high temperature situation of the dry clutch as described above and a weight or rigidity of a vehicle is referred to as a judder.
The hardware characteristics allow a driver to feel a longitudinal vibration of a vehicle to reduce drivability. To solve the above problem, a method of changing a material, and the like of a clutch disk has been used, but may have an effect on power transfer performance of a vehicle.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.